Display device having an electrode partially covering a picture element
An optical switch, e.g., a display cell based on layer displacement or layer break up having at least two different states, in which one fluid, e.g. oil, in a first state adjoins at least a first support plate, and in the second state, another fluid at least partly adjoins the first support plate. Part of an otherwise homogeneous electrode is removed to realize oil motion control.
1. An optical switch for a picture element, the optical switch comprising:
a first transparent support plate;
a second support plate;
a first fluid;
a second fluid immiscible with the first fluid within a space between the first transparent support plate and the second support plate, the second fluid being electroconductive or polar;
a first electrode on at least one of the support plates, the first electrode only partly covering a total area of the picture element leaving a remaining part of the optical switch not covered by the first electrode; and
a second electrode covering at least a portion of the remaining part; and
a pulse generator configured to provide to the first electrode a first pulse having a first pulse width while the second electrode is grounded and, after removal of the first pulse, to provide to the second electrode a second pulse having a second pulse width, wherein the second pulse width is smaller than the first pulse width; and wherein the first electrode is substantially along an entire first edge and an entire second edge of the optical switch, and the second electrode is along a third edge of the optical switch.
2. The optical switch according to claim 1 , wherein the remaining part is one of the corners of a substantially rectangular optical switch.
3. The optical switch according to claim 1 , wherein the remaining part comprises 5% of a total area of the optical switch.
4. The optical switch according to claim 1 , wherein the remaining part comprises 50% of a total area of the optical switch.
5. The optical switch according to claim 1 , wherein the remaining part comprises 10% of a total area of the optical switch.
6. The optical switch according to claim 1 , further comprising at least one further electrode at the remaining part of the optical switch.
7. The optical switch according to claim 6 , further comprising driving means to apply voltages to the first electrode and the further electrode.
8. A display device comprising picture elements, the picture element having the optical switch according to claim 1 .
9. The display device according to claim 8 , further comprising switching devices at the remaining part left clear by the first electrode.
10. The display device according to claim 9 , wherein the remaining part left clear by the first electrode is covered by a black mask.
11. A display comprising a plurality of picture elements, wherein each picture element includes:
two fluids which are immiscible with each other located between support plates;
a first electrode on at least one of the support plates, the first electrode only partly covering a total area of the picture element, leaving a remaining area not covered by the first electrode, wherein the picture elements have remaining areas at substantially same positions so that a first fluid of the two fluids moves towards the same positions of the picture elements upon application of a voltage to the first electrode, wherein the first electrode is substantially along an entire first edge and an entire second edge of the picture element, and the remaining area is along a third edge of the picture element;
a second electrode covering at least a portion of the remaining area; and
a pulse generator configured to provide to the first electrode a first pulse having a first pulse width while the second electrode is grounded and, after removal of the first pulse, to provide to the second electrode a second pulse having a second pulse width, wherein the second pulse width is smaller than the first pulse width.
12. The display of claim 11 , wherein the same positions includes the third edge of each of the picture elements.
13. The display of claim 11 , wherein the same positions includes at least one corner of each of the picture elements.
14. The display of claim 11 , wherein the each picture element further includes a second electrode located at the remaining area, so that application of a voltage to the second electrode moves the first fluid away from the remaining area.
15. The display of claim 14 , wherein the first fluid is oil which is spread over remaining area upon removal of the voltage to the second electrode.